Immune checkpoint blockade targeting PD-1 and PD-L1 has resulted in unprecedented clinical benefit for cancer patients. Anti-PD-1/PD-L1 therapy has become the standard treatment for diverse cancer types as monotherapy or in combination with other anti-cancer therapies, and its indications are expanding. However, many patients do not benefit from anti-PD-1/PD-L1 therapy due to primary and/or acquired resistance, which is a major obstacle to broadening the clinical applicability of anti-PD-1/PD-L1 therapy. In addition, hyperprogressive disease, an acceleration of tumor growth following anti-PD-1/PD-L1 therapy, has been proposed as a new response pattern associated with deleterious prognosis. Anti-PD-1/PD-L1 therapy can also cause a unique pattern of adverse events termed immune-related adverse events, sometimes leading to treatment discontinuation and fatal outcomes. Investigations have been carried out to predict and monitor treatment outcomes using peripheral blood as an alternative to tissue biopsy. This review summarizes recent studies utilizing peripheral blood immune cells to predict various outcomes in cancer patients treated with anti-PD-1/PD-L1 therapy.
Acceleration ; Antigens, CD274 ; Biomarkers ; Biopsy ; Drug-Related Side Effects and Adverse Reactions ; Fatal Outcome ; Humans ; Prognosis ; Programmed Cell Death 1 Receptor

PURPOSE: The efficacy of nivolumab in metastatic renal cell carcinoma (mRCC) has been proven. However, the nivolumab experience in Korean patients with mRCC is still poorly reported. We report initial experiences with the efficacy and safety of nivolumab in patients with mRCC. MATERIALS AND METHODS: We retrospectively reviewed records for 25 patients with mRCC who had failed targeted therapy and were treated by nivolumab (2 mg/kg, every 2 weeks) at a single institution. The primary endpoint was objective response rate (ORR), and secondary endpoints were progression-free survival (PFS), safety profiles, and ORR in a programmed cell death receptor ligand 1 (PD-L1) expression subgroup. RESULTS: The median age was 60 years and 16 patients (64%) were male. Objective responses were achieved in 8 patients (32.0%) (complete response, 1; partial response, 7). Median PFS was 3.0 months (95% confidence interval, 1.46–4.53). Treatment-related adverse events (AEs) of any grade were observed in 19 patients (76.0%) with 6 (24.0%) experiencing grade 3 to 4 treatment-related AEs. In subgroups by PD-L1 expression levels classified as 1% or greater and less than 1%, ORR was 50% and 0%, respectively. CONCLUSIONS: This study showed the efficacy and safety of initial experiences with nivolumab in Korean patients with mRCC who had failed targeted therapy. Our results were comparable to recent clinical trials on nivolumab in mRCC.
Antigens, CD274 ; Carcinoma, Renal Cell ; Cell Death ; Disease-Free Survival ; Humans ; Male ; Neoplasm Metastasis ; Retrospective Studies ; Treatment Outcome

OBJECTIVE: Programmed death-ligand 1 (PD-L1) was expressed in various tumors and antibodies targeting its receptor programmed cell death-1 (PD-1) are emerging cancer therapeutics. This study was designed to evaluate the expression of PD-L1 and its correlation with clinicopathologic features and clinical outcomes in ovarian clear cell carcinoma (OCCC). METHODS: The PD-L1 expression was measured by tissue-microarray-based immunohistochemistry from 122 eligible patients diagnosed with OCCC. The associations of clinicopathologic features with progression-free survival (PFS) and overall survival (OS) were analyzed by Kaplan-Meier method and multivariate analysis was further performed by Cox regression model. RESULTS: Overall, high PD-L1 expression (PD-L1(high)) was observed in 44.7% (55/123) of OCCC patients, and was strongly associated with advanced stages (p=0.020), positive ascitic fluid (p=0.016), platinum-resistant (PR) disease (p=0.045), and recurrence (p=0.038). Moreover, patients with PD-L1(high) were associated with poorer OS (hazard ratio [HR]=2.877; p=0.001) and PFS (HR=1.843; p=0.021) than those with low PD-L1 expression (PD-L1(low)). In subgroup analysis, PD-L1(high) patients experienced a poorer PFS (HR=1.926; p=0.044) and OS (HR=2.492; p=0.021) than PD-L1(low) cases among advanced stages (III–IV), but this difference was not observed in stage I–II patients. Meanwhile, PD-L1(high) was associated with poorer prognosis than PD-L1(low) in PR patients (OS, HR=2.253; p=0.037; PFS, HR=1.448; p=0.233). Multivariate analysis revealed that PD-L1(high) and advanced stages (III–IV) were adverse independent prognosticators for both PFS (HR(PD-L1)=2.0; p(PD-L1)=0.038; HR(stage)=10.2; p(stage)<0.001) and OS (HR(PD-L1)=3.0; p(PD-L1)=0.011; HR(stage)=14.3; p(stage)<0.001). CONCLUSION: PD-L1(high) might serve as a risk factor for PFS and OS in patients with OCCC. It is possible that immunotherapy targeting PD-L1 pathway could be used in OCCC.
Adenocarcinoma, Clear Cell ; Antibodies ; Antigens, CD274 ; Ascitic Fluid ; Disease-Free Survival ; Humans ; Immunohistochemistry ; Immunotherapy ; Methods ; Multivariate Analysis ; Ovarian Neoplasms ; Prognosis ; Recurrence ; Risk Factors

OBJECTIVE: Programmed cell death-ligand 1 (PD-L1) is expressed in tumor cells and has been shown to predict clinical outcomes of several types of malignancies. The aim of this study was to investigate the effects of carbon-ion (C-ion) beam irradiation on PD-L1 expression in human uterine cervical adeno/adenosquamous carcinoma (UCAA) cells and clinical samples and to identify the prognostic factors for outcomes after C-ion radiotherapy (CIRT).METHODS: The effects of C-ion irradiation on PD-L1 expression in human UCAA and cervical squamous cell carcinoma cells were examined by flow cytometry. We examined PD-L1 expression in UCAA biopsy specimens from 33 patients before CIRT started (pre-CIRT) and after 12 Gy (relative biological effectiveness [RBE]) irradiation (post-12Gy-C) in 4 fractions of CIRT to investigate the correlation between PD-L1 status and clinical outcomes.RESULTS: The PD-L1 expression was upregulated by C-ion beam in a dose-dependent manner in HeLa and SiHa cells through phosphorylated Chk1. The overall frequencies of pre-CIRT and post-12Gy-C PD-L1 positivity were 45% (15/33) and 67% (22/33), respectively. The post-12Gy-C PD-L1 expression was significantly elevated compared to the pre-CIRT PD-L1 expression. There was no significant relationship between the pre-CIRT PD-L1 status and clinical outcomes, such as local control (LC), progression-free survival (PFS), and overall survival (OS). However, the post-12Gy-C PD-L1 expression had better correlation with PFS, but not with LC and OS.CONCLUSION: CIRT can induce PD-L1 expression in UCAA and we propose that PD-L1 expression after starting CIRT may become as a predictive prognostic marker in CIRT for UCAA.
Antigens, CD274 ; Biopsy ; Carcinoma, Squamous Cell ; Disease-Free Survival ; Flow Cytometry ; Heavy Ion Radiotherapy ; Humans ; Radiotherapy ; Treatment Outcome ; Uterine Cervical Neoplasms

PURPOSE: Immune suppression is common in patients with advanced breast cancer but the mechanisms underlying this phenomenon have not been sufficiently studied. In this study, we aimed to identify B7 family members that were able to predict the immune status of patients, and which may serve as potential targets for the treatment of breast cancer. We also aimed to identify microRNAs that may regulate the expression of B7 family members. METHODS: The Cancer Genome Atlas data from 1,092 patients with breast cancer, including gene expression, microRNA expression and survival data, were used for statistical and survival analyses. Polymerase chain reaction and Western blot were used to measure messenger RNA and protein expression, respectively. Luciferase assay was used to investigate direct microRNA target. RESULTS: Bioinformatic analysis predicted that microRNA (miR)-93, miR-195, miR-497, and miR-340 are potential regulators of the immune evasion of breast cancer cells, and that they exert this function by targeting CD274, PDCD1LG2, and NCR3LG1. We chose CD274 for further investigations. We found that miR-195, miR-497, and CD274 expression levels were inversely correlated in MDA-MB-231 cells, and miR-195 and miR-497 expressions mimic inhibited CD274 expression in vitro. Mechanistic investigations demonstrated that miR-195 and miR-497 directly target CD274 3′ untranslated region. CONCLUSION: Our data indicated that the level of B7 family members can predict the prognosis of breast cancer patients, and miR-195/miR-497 regulate CD274 expression in triple negative breast cancer. This regulation may further influence tumor progression and the immune tolerance mechanism in breast cancer and may be able to predict the effect of immunotherapy on patients.
Antigens, CD274 ; B7 Antigens ; Blotting, Western ; Breast Neoplasms ; Computational Biology ; Gene Expression ; Genome ; Humans ; Immune Evasion ; Immune Tolerance ; Immunotherapy ; In Vitro Techniques ; Ligands* ; Luciferases ; MicroRNAs ; Polymerase Chain Reaction ; Prognosis ; RNA, Messenger ; Triple Negative Breast Neoplasms* ; Untranslated Regions

PURPOSE: The purpose of this study was to evaluate the relationships between the resistance of anaplastic lymphoma kinase (ALK)‒positive non-small cell lung cancer (NSCLC) to ALK inhibitors and the programmed cell death-1/programmed cell death–ligand 1 (PD-L1) pathway, we evaluated alterations in PD-L1 following acquisition of resistance to ALK inhibitors in ALK-positive lung cancer. MATERIALS AND METHODS: We established ALK inhibitor-resistant cell lines (H3122CR1, LR1, and CH1) by exposing the parental H3122 ALK-translocated NSCLC cell line to ALK inhibitors. Then, the double-resistant cell lines H3122CR1LR1 and CR1CH1 were developed by exposing the H3122CR1 to other ALK inhibitors. We compared the alterations in PD-L1 expression levels using western blotting, flow cytometry, and quantitative polymerase chain reaction. We also investigated gene expression using RNA sequencing. The expression of PD-L1 in the tumors from 26 ALK-positive metastatic NSCLC patients (11 ALK inhibitor-naïve and 15 ALK inhibitor-resistant patients) was assessed by immunohistochemistry and analyzed. RESULTS: PD-L1 was expressed at higher levels in ALK inhibitor-resistant cell lines than in the ALK inhibitor-naïve parental cell line at the total protein, surface protein, and mRNA levels. Furthermore, PD-L1 expression in the double-resistant cell lines was much higher than that in the single resistant cell lines. RNA sequencing demonstrated that expression of immune-related genes were largely involved in ALK inhibitor resistance. The mean value of the PD-L1 H-score was 6.5 pre-treatment and 35.0 post-treatment, and the fold difference was 5.42 (p=0.163). CONCLUSION: PD-L1 expression increased following acquisition of ALK inhibitor resistance in ALK-positive NSCLC cell lines and tumors.
Antigens, CD274 ; Blotting, Western ; Carcinoma, Non-Small-Cell Lung ; Cell Line ; Drug Resistance ; Flow Cytometry ; Gene Expression ; Humans ; Immunohistochemistry ; Lung Neoplasms ; Lung ; Lymphoma ; Parents ; Phosphotransferases ; Polymerase Chain Reaction ; RNA, Messenger ; Sequence Analysis, RNA